<![CDATA[The quasi experiment research about the effectivity of scientific approach on buffered solutionsin increasing flexibility thinking ability was conducted by using non equivalent control group design.The 11th grade of MIA1 and MIA3 as the sample classes of this research were obtained from five classes of the 11thgrade of MIA at SMA YP Unila for 2014/2015 academic year. The result of this research showed that the average n-Gain in the experimental class was 0.65 and in the control class was 0.32. Because of the average n-Gain in the experimental and control classes were different statistically, it was concluded that learning with scientific approach on buffer topic was effective in increasing flexibility thinking ability.Penelitian kuasi eksperimen tentang pendekatan ilmiah dengan materi larutan penyangga untuk meningkatkan kemampuan berpikir luwes dilakukan dengan desain Non-Equivalent Control Group. Sampel dari penelitian ini adalah kelas XI MIA1 dan XI MIA3 diperoleh dari lima kelas pada kelas XI MIA SMA YP Unila tahun pelajaran 2014/2015. Hasil penelitian menunjukkan bahwa rata-rata n-Gain kelas eksperimen sebesar 0,65 dan kelas kontrol sebesar 0,32. Karena rata-rata n-Gain kelas eksperimen dan kelas kontrol berbeda secara statistik, maka dapat disimpulkan bahwa pem-belajaran dengan menggunakan pendekatan ilmiah pada materi larutan penyangga efektif dalam meningkatkan kemampuan berpikir luwes.Kata kunci: keterampilan berpikir luwes, larutan penyangga, pendekatan ilmiah.]]>
